Tubular buoy

ABSTRACT

A life buoy, anchored buoy, or similar article of manufacture having at least one tube containing pressurized gaseous material within a strength-providing waterproof envelope, and preferably comprising foam plastic between the envelope and portions of the tube. When only one tube is used it optionally may be doughnutshaped as in FIGS. 4 to 8 or helically wound as in FIG. 2. When the tubular means comprises two or more tubes they may be concentric as in FIG. 1. Optionally there may be fixed at the center of the tubular means a strength-providing cylinder, openended or closed at one or both ends, or a sealed compartment, or a sphere. The compartment optionally may contain survival materials (in a life buoy) or a wave motor, electric generator and battery (in an anchored buoy having an electric light, bell, horn or the like).

United States Patent [191 Moore Apr. 16, 1974 TUBULAR BUOY [76] Inventor: Alvin Edward Moore, 916 Beach f' Blvd waveland, Miss 39576 Asszstant Exammer-Stuart M. Goldstein [22] Filed: Feb. 11, 1972 57 ABSTRACT [21] Appl. No.: 225,386 1 A life buoy, anchored buoy, or similar article of manu- Related U.S- Appll Dam facture having at least one tube containing pressurized [63] fgy gwg-wr f 3 rg 3 gaseous material within a strength-providing water- W 16 IS a C01] mua lon-m-pa 0 81'. 0. f l d ferabl com risin foam proo enve ope, an pre y p g p 531564 March 1966 tie between the envelope and portions of the tube.

When only one tube is used it optionally may be CCll doughnut shaped as in FIGS 4 to 8 or helically wound as in FIG. 2' when the tubular means comprises two [58] Field of Search 9/8 R, 2 A, 11 A or more tubes y y be concentric as in FIG. 1 [56] References Cited Optionally there may be fixed at the center of the tubular means a strength-providing cylinder, open-ended UNITED STATES PATENTS or closed at one or both ends, or a sealed compart- 2,'7l5,231 8/1955 Marston 9/11 A ment, or a sphere. The compartment optionally may 2,814,055 11/ 1957 Phillips 9/3 R contain survival materials (in a life buoy) or a wave 3'510'893 5/1970 Moore A motor, electric generator and battery (in an anchored Moore y having a electric e orn or the e) FOREIGN PATENTS OR APPLICATIONS 712,981 9/1966 ltaly 9/8 26 13 Drawmg Figures TUBULAR BUOY This patent application is a continuation in part of application Ser. No. 23,789, filed on Mar. 30, 1970, which was a continuation in part of application Ser. No. 531,564, filed on Mar. 3, I966 now Pat. No. 3,503,825 Mar. 3 l 1970, entitled Method of Making Light- Weight Article. FIGS. 4, 5, 8, 8A, 9, 11 and 12 are copies of FIGS. 6, 10, 5, 15, 7, 8 and 9, respectively, of application No. 23,789; and FIGS. 1, 3, 6, 7 and are somewhat similar to the structure of FIGS. 1, 3 and 10 of this prior application. FIGS. 5, 9, 11 and 12 of the present application are also copies of FIGS. 6, 4, 5 and 5A of application No. 531,564. These continuation-inpart features of the present application pertain to invention required to be divided from the said prior applications.

Some objects of the present invention are to provide: a very light-weight, strong and long-lasting life buoy, anchored buoy; l or similar article of manufacture, comprising tubular means having a high degree of buoyancy, within waterproof skin means (a casing or envelope), preferably with foam plastic between portions of the tubular means and the casing or envelope; 2. a buoy or the like having structure of the type of 1 above, in which the tubular means comprises a dough nutshaped tube or tubes; 3 a buoy or similar structure as'in l or 2, in which the tubular means comprises at least one helically-wound tube containing gaseous material under above-atmospheric pressure; 4 structure as in l, 2 017.3, in which the tubular means is inflated with lighter-than-air gas; 5 structure of the above type, comprising a central cylinder or storage compartment; 6 structure as in 5 above in which said skin means and the central cylinder or compartment are of strong wall material, and inflated walls'of the tubular means comprise extensible material, e.g., resilient rubber or other plastic, the expansion of these tubular walls being limited by the outer skin meansand the compartment or cylinder. The foregoing and other objects of the invention willbe more fully apparent from the following detailed description of the invention and the accompanying drawings. Y

Inthese drawings:

FIG. 1 is a top planview ofone form of the invention, with the major part of its upper skin broken away to expose the tubular means;

FIG. 2' is a view similar to FIG. 1, illustrating a variation of the encased tubular means;

FIG. 3 is 'a view in section from the plane 3-3 of FIG. 1 (and is somewhat similar to a cross section of FIG. 2);

FIG..4 is a sectional view from a median plane thru a second form of the invented structure;

FIG. 5 is a, sectional view from a median plan thru a modification of the structure of FIG. 4;

FIG. 6 is a sectional view of another modification of the invention form of FIG. 4;

FIG. 7 is a vertical, detail, sectional view of any of the tubular-buoy forms of FIGS. 1 to 6, showing one type of the central compartment and an optional chain, usable in anchored buoys;

FIG. 8 is a plan view of the doughnut-shaped type of tubular means;

FIG. 8A is a sectional view from a median plane thru another form of the buoy or similar article;

FIG. 9 is a sectional view of a gas-containing ball or cylinder, usable alone or in construction of the structure of FIGS. 1 to 7. (FIG. 9 also may be considered to be a cross-sectional view of the type of structure of FIG. 11.)

FIG. 10 is a sectional detail view of a modification of the central compartment of FIG. 7;

FIG. 11 is a sectional view of another type of construction unit that may be utilized as a central element of the buoy or the like (this unit also being optionally usable with the chain of FIG. 7 as a spar buoy);

FIG. 12 is an end elevational view of the unit of FIG. 11, showing an optional end-view configuration of this unit.

In each of its forms the invention comprises: outer skin means (an envelope or casing), indicated at 1 in FIGS. 1, 2, 4 to 6, and 8A, and in FIGS. 3, 7 and 10 at 2A, 2B, 2C; tubular means, shown in FIGS. 1,3 and 4 to 6, 8 and 8A at 4, and in FIG. 2 at 4A; gaseous material, comprising gas or gas-cell-containing foam plastic, inside the tubular means; optional and preferable foam plastic, 5, between the tubular means and the skin means; an optional, strength-providing cylinder or compartment in the middle of the article; an optional handle, 7, usable as an attachment device (for holding the article on a bulkhead of a vessel when it is a life buoy and for aid in a survivors holding and/or mounting the buoy when it is in the water); and an optional chain, 8, attached to the bottom of the article when it is used as an anchored buoy.

The skin means (1 or 2) in the structure of each of FIGS. 1 to 12 optionally may comprise: molded plastic; plastic or metal or plywood sheets; or sheets of smallmesh textile or metallic netting or fabric; impregnated, coated and waterproofed with plastic. When of plastic this casing preferably is molded and of dense, stiffly resilient plastic. When of sheets it preferably comprises: individual upper and lower skins (2A, 2B); and an endlessly curved band (2C, optionally flexible, optionally stiffly resilient), between and fixed to the edges of 2A and 2B, preferably with bonding material (epoxy glue or putty, welding, brazing or solder).

The tubular means of each of the figures preferably comprises tubular walls that are thin and light in weight, optionally non-extensible or expansible. Optionally in each case their material may be: molded, resilient or non-resilient plastic preferably substantially impermeable to gas, e.g., fiber-reinforced plastic, or resilient rubber that is slowly permeable to gas; diepressed sheets of metal or of plasticof the type referred to above, hermetically joined by bonding material; thin molded or die-formed aluminum, aluminum alloy, very thin iron, steel or copper; blown glass; balloon cloth (nylon or the like), coated and impregnated with rubber or other plastic).

When it is metal or dense plastic that is practically impermeable to gas it may be inflated with air or lighter-than-air gas such as helium, preferably at a pressure that is well above that of the atmosphere, for example, of 5 to 30 pounds per square inch, and then the inflation hole, tube or valve is permanently sealed. This sealing may be by application of epoxy glue or by welding, brazing, soldering, or fusing if a type of plastic is used that is meltable by heat. If the tube is integrally made, for instance by the molding method of the present inventors Pat. No. 3,503,825, it is hermetically sealed in a step of this method.

Another example of a method of making the doughnut-shaped tubes comprises the following steps: 1. diestamping or molding two equal, half-tube parts, each having an annular'flange around its radially outer edge and another concentric annular flange around its radially inner edge; 2. placing the flanges one above the other to form the doughnut-shaped ring; 3. hermetically uniting the contacting faces of the flanges, except at an inflation hole or little pipe or valve tube, by welding, brazing, soldering, fusing'of plastic, or epoxy cement;.4. inflating the tube with selected gas (or with gas-cellscontainingfoam plastic); and 5. sealing the inflat ion inlet by bonding material or fused plastic.

Another type of the doughnut-shaped tube is made, somewhat like an automobile tire tube, by molding it of resilient synthetic or naturalrubber; but unlike a tire tube, itsvalve tube,.in each of the forms of the invention, optionally may be located not at the doughnutlike hole, but instead in the sidewall or in the radially outer-wall of the tube. In FIGS; 1, 2, 8 and 8A these inflation inlets'9-are shown as in sidewalls of the curvedaxis tubes. The valve 9 A of FIG. 4 is shown as optionally in a radially outer portion of the tube; and in FIG. 6 the valve 9B'is in an interior portion of a tubes walls; but in these figures also, the valve optionally may be in any one of these three positions; but when the tube. is to be. concentrically nested with other tubes as in FIG. 1' the valve is preferably located in a tubular sidewall.

The tubular means of FIG. 2 is helically wound. It may be of any of the abovedescribed tube-wall materials, and optionallyrnay bemolded or die-formed in two parts and their edgesbonded together; but preferably the tube is of flexible or resilient extruded plastic or ductile metal. It may be extruded in a curve somewhat like that of its final form by guiding it into a curve as it comes from the extrusion die. The ends of the tubes may be in the form of disks 10, fixedto the maintubebody by bonding material, or (optionally) the tube ends may be flattened and sealed by bonding material or fused plastic. Optionally, this, tubular means of FIG. 2 may comprise two equal tubes joined by end disks; but preferably onlyone tube is used. And optionally the valve 12 may be in a tube-end disk; but preferably only the sidewall .valve 9 is utilized. The sidewall valves of FIGS. 1 to 3, 8 and 8 A are out of the way of adjacent tubes when these are concentric; and in an article containing only one tube the sidewall valve is conveniently accessible for inflation.

The gaseous material that is inside the tubular means preferably has a pressure well above that of the atmosphere. This material optionally may be air or heavierthan-air gas, or gas-cell-containing foam plastic (substantially rigid orstifi'ly resilient and optionally under above-atmospheric pressure); but preferably it comprises pressurized ligher-than-air gas, such as helium, nitrogen hydrogen, or hydrogen mixed with a small amount of inert gas.

Although the filler material around all or most of the tubular convolutions may be very light-weight concrete, comprising cement (epoxy or Portland) and very light-weight aggregate, e .g., expanded shale or shredded or ground plastic), it preferably is foam plastic (optionally resilient but preferably substantially rigid). When, as in FIG 8A, this filler material is in the central space of a doughnut-shaped tube, helium or other lighter-than-air balloons 14 are preferably imbedded in the foam plastic or light-weight concrete.

In each of the disclosed forms the space in the center of the curved tubular means optionally may be: 1. filled with foam plastic or conrete, as in FIG. 8A; 2. hollow and open from top to bottom, as in the configuration of a presently common life buoy (the articles of FIGS. 4 to 6 optionally may be in this configuration or their central spaces may contain a cylinder, compartment, or a central buoyant element like that of FIG. 9 or FIG. 1 1); or contain a buoyant and/or storage compartment of the general type of FIGS. 3, 6, 7 and 10. The compartment of FIGS. 3, 6, 7 and 10 comprises a molded plastic or metal housing 16 (16A) and a detachable lid or cover that may be watertightly sealed to the top of the box. This metallic or plastic cover in each of FIGS. 3, 6, 7 and 10 may be sealed against a flexible, waterproof gasket or band of plastic or the like; or it may be a snap-on lid of the type used in common paint cans. In FIG. 10, the box 16A has a screwthreaded neck 18 that extends above the top of the skin means 2A; and on these threads the compartment cover 20 is screwed downward into sealing contact with the gasket 21. In FIG. 7, the lid 22 is screwed down into tight contact with the gasket 24 by turning the handles 25 and screw threaded bolts 26, thus forcing the plastic or metal elements 27, glued or bonded to 22 (or to bolt ends), against the lid 22, the tightly sealing the cover against the gasket. When the compartment and the skin means 1 are of molded plastic the parts 213 and 2C of the skin means and the box 16 are preferably molded as an integral unit, and the lid (20, 22A) is separately formed. In FIG. 3 the snap-on lid 22A has a knob 28 by which the cover may be pulled off the box or can without a tool. When, optionally, the tubular means is of the abovementioned expansible material, the housing (16,16A) and the skin means (1, 2), being in reacting contact with the tube or tubes, of course have sufficient strength to withstand disrupting tendency of the tubular member to expand.

FIGS. 9, 11 and 12 illustrate an article of manufacture that may be utilized as an element to fill the central space of the buoy or the like of FIGS. 1 to 8A, or used for other purposes (for example, as a balloon, ball, toy, spar buoy comprising also an anchor chain), a buoyant cable, or other buoyantdevice. FIG. 9 may be considered as a cross section of the elongated article of FIG. 11 or of a spherical article; when spherical or cylindrical it may have dimensions to fit within and be glued to inner surfaces 30 of the ring 4 that is adjacent to the central space (FIGS. 1, 2 and 5). When it is a somewhat elongated cylinder it preferably does not extend below the level of the lower skin of the buoy, but instead projects upward above the top skin sufficiently for a survivor on the buoy to hold the cylinder for aid in staying on the buoy in rough water. In this latter instance, the central element serves as an upper buoyant element, which, together with the ballast described below, tends to prevent capsizing of the buoy, loaded on its top surface; and the lifeline 32 then may or may not be a part of the structure.

The ball or cylinder of FIGS. 9 and 11 comprises: a skin 34, of any of the above-described flexible materials (or a coat of waterproofing paint); foam plastic 5A and an inner inflated core, (an inner hollow sphere or cylinder, 35, 35A), tilled with helium, air or other gas, preferably under pressure above that of the atmosphere. This inflated core optionally may be made by the method of Pat. No. 3,503,825. When it is a cylinder 35A it may be a sealed metallic, plastic or glass can, and may be attached to an anchor chain 8, forming a spar buoy.

The chain 8, an optional feature in each of the structures when it is used as an anchored buoy may be fixed to the bottom of the lower skin 2B and to the box 16 by the bonding material 3% (epoxy, welding, brazing or the like), with or without bolts thru and sealed to the bottom of the box. Optionally, such a chain also may be fixed in this manner to an end of the unit 35A and sealingly fixed to and extending thru the foam plastic 5A and skin means 34.

When the article is a buoy, ballast, of aid in preventing capsizing, optionally may be provided in each of the forms of the invention. When, the buoy comprises a central compartment this ballast may be contained in the box and/or comprise a ring of lead sheeting, apertured at its center for fitting around the compartment and lying snugly on the top surface of the lower skin 23. Alternatively, the element 2B may be made of lead sheet and fixed to lighter-weight upper elements 2A and 2C. When ballast is carried in the compartment it may comprise a compartment-bottom lead sheet and- /or tools or other heavy equipment of aid in survival; or a combined wave motor and electric generator (40, comprising a wave-motion-shifted armature) and abattery 42 may be utilized and serve as ballast.

in the claims: the term skin means refers to an integral skin or a plurality of skins (of thin or thick material) that are joined; the word plastic means any type of natural or synthetic rubber or other plastic; the term tubular means signifies a single tube, endless or having ends, of any shape in cross section, open-ended or sealed, or a plurality of tubes of this type; gaseous material: any pure gas, air, other gaseous mixture or gascell-containing foam plastic; and fabric" means any kind of textile or metallic cloth or mesh.

- Iclaim:

l. Anarticle of manufacture, including:

skin means of waterproof, article-strength-providing, substantially non-extensible material, defining a space in the interior of. said article, comprising: a curved, sidewall skin; and a pair of upper and lower skins, above and below said space;

housing of stiff, substantially nomextensible, article-strength-providing material, located in a middle portion of said space and adapted to hold useful'objects, comprising: a curved sidewall; and an upper, waterproof cover, capable of being opened; the said upper skin having a hole of an area at least large enough to permit opening of said cover and access to said housing; tubular means in said space and within said skin means, comprising nested, tubular convolutions of which: the innermost convolution bears against said curved sidewall of the housing; the outermost convolution bears against said curved sidewall skin; and each of the intermediate convolutions has an outer surface substantially in continuous contact with an inner surface of a surrounding convolution; and the said convolutions have upper and lower surfaces that bear against said upper and lower skins; and gaseous material inside said tubular means.

2. A device as set forth in claim 1, in which each of said convolutions is a doughnut-shaped tube, having a different circumference from that of each of the other nested tubes.

3. A device as set forth in claim 1, in which said convolutions are turns of a spirally arranged tube.

4. A device as set forth in claim 1, in which the said tubular means comprises at least one gaseous-material inlet located on a sidewall portion of a said nested convolution.

5. A device as set forth in claim 1, in which the said article is a buoy.

6. Structure as set forth in claim 1, in which the said article is a life-saving device, further including a lifeline, fixed to said skin means, bordering a space above said upper skin that is at least as large as most of this skins area.

7. A device as set forth in claim 1, in which said skins are integral and comprise plastic.

8. A device as set forth in claim 7, in which said housing comprises molded plastic.

9. A device as set forth in claim 1, in which said housing comprises metal.

10. A device as set forth in claim 1, in which:

said housing comprises a metal can;

and said cover is a metallic lid capable of being forced into sealing position in a groove of said lid.

11. A device as set forth in claim 1, in which said housing sidewall and said cover have interconnected portions, capable of being manipulated for sealing closure of said housing and for opening the housing.

12. A device as set forth in claim 11, in which said interconnected portions comprise flanges of said cover said housing sidewall and interengageable screwthreads on said flanges.

13. An article as set forth in claim 1, in which said tubular means comprises metal.

14. A device as set forth in claim 1, in which the said article is a life buoy, and said housing is adapted for the storage of survival materials.

15. A device as set forth in claim 1, in which the said article is a buoy, and comprises an anchor chain, fixed to a bottom portion of the article.

. 16. An article as setforth in claim 1, in which:

the said gaseous material is under above-atmospheric pressure;

said tubular means is of flexible, extensible material,

has a tendency to expand under said pressure-and has a portion inwardly exerting tube-expanding force toward said housing;

and said housing limits expansion of the tube toward the articles center.

17. An article as set forth in claim 1, comprising foam plastic between portions of said tube and skin means.

18. A device as set forth in claim 1, in which the article is a buoy, and comprises ballast located at a lower part of the buoy.

19. An article as set forth in claim 1, in which said gaseous material comprises helium.

20. An article of manufacture, including:

an outer waterproof casing of dense, substantially non-extensible, article-strength-providing material, having an interior space, comprising:

a curved sidewall casing portion;

an upper portion having a hole in its middle part;

and a lower, substantially flat portion; a housing in a middle part of said space, adapted to hold useful objects, of substantially non-extensible, article-strength-providing material and comprising: sidewalls, connected to said upper portion at borders of said hole; an upper housing part, comprising a rim, providing an opening to the interior of said housing; and a cover, accessible from the exterior of said outer casing, sealably engageable with said rim for waterproofedly closing the housing; a plurality of concentric, doughnut-shaped tubes, nested within said casing, each adjacent pair of said tubes having annular sidewall portions that are in contact around the common center line of their curvatures, and having upper and lower tubular portions that bear against said upper and lower casing portions; the outermost one of said tubes bearing against said curved sidewall casing portion;

and the innermost one of said tubes bearing against said housing;

and gaseous material in said tubes.

21. An article as set forth in claim 20, in which said tubes comprise: metal, and said gaseous material is permanently sealed within said tubes.

22. An article as set forth in claim 20, in which said tubes are of expansible material and said gaseous material is under above-atmospheric pressure.

1 23. An article as set forth in claim 20, further including foam plastic within said casing, in which said tubes are imbedded.

24. An article as set forth in claim 20, further including a lifeline fixed to said upper casing portion.

25. An article of manufacture, including:

an outer waterproof casing of article-strengthproviding material, having an interior space, comprising:

a curved sidewall casing portion; an upper portion having a hole in its middle part; and a lower, substantially flat portion;

a housing in a middle part of said space, adapted to hole useful objects, of substantially non-extensible, article-strength-providing material, comprising: sidewalls, connected to said upper portion at said hole;

an upper housing part, comprising a rim, providing an access opening to the interior of said housing;

and a cover, accessible from the exterior of said outer casing, sealably engageable with said rim for waterproofedly closing said housing; Tubular means within said interior space of the casing, comprising at least one spirally arranged tube, the said tube having: an inner end adajcent to and contacting a portion of said housing sidewalls; an outer end adjacent to and contacting an interior portion of said sidewall casing portion; a and a plurality of convolutions between said outer and inner ends; the said convolutions having side portions that are substantially in continuous contact from one of said ends to the other; each of said convolutions contacting said upper and lower casing portions; and gaseous material in said tubular means. 26. An article as set forth in claim 25, in which said tube is of expansible material and said gaseous material is under above-atmospheric pressure.

Patent No. 3,803,651 'Dated April 74 Alvin Edward Moore lnventor(s) It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

Column 1, line 19, before 'a very" insert l. line 20, cancel "1''. Column 4, line 5, "conrete" should read concrete line 28, "the", second occurrence, should read and Column 6, line 34, "said" should read and Column 8, line 7, "hole" should read hold line 24, "a" should be canceled.

Signed and sealed this 24th day of September 1974.

(SEAL) Attest:

McCOY M. GIBSON JR. 7 C. MARSHALL DANN Attesting Officer Commissioner of Patents FORM po'mso 0459) USCOMM-DC wan-Poo U.5. GQVIRNMENT PRINTING OFFICE O 

1. An article of manufacture, including: skin means of waterproof, article-strength-providing, substantially non-extensible material, defining a space in the interior of said article, comprising: a curved, sidewall skin; and a pair of upper and lower skins, above and below said space; a housing of stiff, substantially non-extensible, articlestrength-providing material, located in a middle portion of said space and adapted to hold useful objects, comprising: a curved sidewall; and an upper, waterproof cover, capable of being opened; the said upper skin having a hole of an area at least large enough to permit opening of said cover and access to said housing; tubular means in said space and within said skin means, comprising nested, tubular convolutions of which: the innermost convolution bears against said curved sidewall of the housing; the outermost convolution bears against said curved sidewall skin; and each of the intermediate convolutions has an outer surface substantially in continuous contact with an inner surface of a surrounding convolution; and the said convolutions have upper and lower surfaces that bear against said upper and lower skins; and gaseous material inside said tubular means.
 2. A device as set forth in claim 1, in which each of said convolutions is a doughnut-shaped tube, having a different circumference from that of each of the other nested tubes.
 3. A device as set forth in claim 1, in which said convolutions are turns of a spirally arranged tube.
 4. A device as set forth in claim 1, in which the said tubular means comprises at least one gaseous-material inlet located on a sidewall portion of a said nested convolution.
 5. A device as set forth in claim 1, in which the said article is a buoy.
 6. Structure as set forth in claim 1, in which the said article is a life-saving device, further including a lifeline, fixed to said skin means, bordering a space above said upper skin that is at least as large as most of this skin''s area.
 7. A device as set forth in claim 1, in which said skins are integral and comprise plastic.
 8. A device as set forth in claim 7, in which said housing comprises molded plastic.
 9. A device as set forth in claim 1, in which said housing comprises metal.
 10. A device as set forth in claim 1, in which: said housing comprises a metal can; and said cover is a metallic lid capable of being forced into sealing position in a groove of said lid.
 11. A device as set forth in claim 1, in which said housing Sidewall and said cover have interconnected portions, capable of being manipulated for sealing closure of said housing and for opening the housing.
 12. A device as set forth in claim 11, in which said interconnected portions comprise flanges of said cover said housing sidewall and inter-engageable screwthreads on said flanges.
 13. An article as set forth in claim 1, in which said tubular means comprises metal.
 14. A device as set forth in claim 1, in which the said article is a life buoy, and said housing is adapted for the storage of survival materials.
 15. A device as set forth in claim 1, in which the said article is a buoy, and comprises an anchor chain, fixed to a bottom portion of the article.
 16. An article as set forth in claim 1, in which: the said gaseous material is under above-atmospheric pressure; said tubular means is of flexible, extensible material, has a tendency to expand under said pressure, and has a portion inwardly exerting tube-expanding force toward said housing; and said housing limits expansion of the tube toward the article''s center.
 17. An article as set forth in claim 1, comprising foam plastic between portions of said tube and skin means.
 18. A device as set forth in claim 1, in which the article is a buoy, and comprises ballast located at a lower part of the buoy.
 19. An article as set forth in claim 1, in which said gaseous material comprises helium.
 20. An article of manufacture, including: an outer waterproof casing of dense, substantially non-extensible, article-strength-providing material, having an interior space, comprising: a curved sidewall casing portion; an upper portion having a hole in its middle part; and a lower, substantially flat portion; a housing in a middle part of said space, adapted to hold useful objects, of substantially non-extensible, article-strength-providing material and comprising: sidewalls, connected to said upper portion at borders of said hole; an upper housing part, comprising a rim, providing an opening to the interior of said housing; and a cover, accessible from the exterior of said outer casing, sealably engageable with said rim for waterproofedly closing the housing; a plurality of concentric, doughnut-shaped tubes, nested within said casing, each adjacent pair of said tubes having annular sidewall portions that are in contact around the common center line of their curvatures, and having upper and lower tubular portions that bear against said upper and lower casing portions; the outermost one of said tubes bearing against said curved sidewall casing portion; and the innermost one of said tubes bearing against said housing; and gaseous material in said tubes.
 21. An article as set forth in claim 20, in which said tubes comprise metal, and said gaseous material is permanently sealed within said tubes.
 22. An article as set forth in claim 20, in which said tubes are of expansible material and said gaseous material is under above-atmospheric pressure.
 23. An article as set forth in claim 20, further including foam plastic within said casing, in which said tubes are imbedded.
 24. An article as set forth in claim 20, further including a lifeline fixed to said upper casing portion.
 25. An article of manufacture, including: an outer waterproof casing of article-strength-providing material, having an interior space, comprising: a curved sidewall casing portion; an upper portion having a hole in its middle part; and a lower, substantially flat portion; a housing in a middle part of said space, adapted to hole useful objects, of substantially non-extensible, article-strength-providing material, comprising: sidewalls, connected to said upper portion at said hole; an upper housing part, comprising a rim, providing an access opening to the interior of said housing; and a cover, accessible from the exterior of said outer casing, sealably engageable with said rim for waterproofedly closing said housing; Tubular means within said interior space of the casing, comprising at least one spirally arranged tube, the said tube having: an inner end adajcent to and contacting a portion of said housing sidewalls; an outer end adjacent to and contacting an interior portion of said sidewall casing portion; a and a plurality of convolutions between said outer and inner ends; the said convolutions having side portions that are substantially in continuous contact from one of said ends to the other; each of said convolutions contacting said upper and lower casing portions; and gaseous material in said tubular means.
 26. An article as set forth in claim 25, in which said tube is of expansible material and said gaseous material is under above-atmospheric pressure. 